1. Field of the Invention
The present invention relates to sorting compartments and to a procedure for the use of such compartments for sorting timber. In this procedure, a sorting compartment is filled with timber pieces, after which it is opened and the timber lot that has accumulated into it is allowed to discharge on the take-up equipment, with which the timber lot is then removed to be further processed. After discharging, the compartment is closed for the reception of the next timber lot.
2. Description of the Prior Art
In timber sorting installations, various different compartment sections with compartments into which timber is directed according to its size and type are known. For instance, such installations are known wherein a compartment bottom comprises a trap door hinged at its one edge, while the other end of the compartment is suspended by flexible supporters for opening and closing the compartment by raising and lowering these flexible supporters. For this kind of compartment system, we refer to the applicant's Finnish Patent Publication No. 44352.
As it has been noticed that, due to the high dropping altitude, timber may break in sorting compartments described above, wherefor elevator- or lift-type compartments have been taken into use, as in these, the timber lot is cautiously lowered on the take-up level, which may for instance, be a carriage or a conveyor, with which the timber lot is then removed to be further processed. Such sorting compartment systems have recently been developed in which the compartments are bags composed of flexible supporters, said bags being expanded as timber accumulates into the bag. Examples of bag compartments of this type are described in the applicant's Finnish patent application No. 773917, SE Publication prints Nos. 367,931 and 405,815, and U.S. Pat. No. 3,776,379. However, in these well-known compartment constructions, there have been such drawbacks that they have not come into general use. As an example of these drawbacks, one can mention complicated and expensive structures, that also have an unfavorable effect on the reliability of operation. Another drawback is that as, in equipment known so far, the drive mechanisms of the flexible supporters wind up only one end of the supporter, and rewinding that must take place after the compartment has been emptied is too slow for modern highly efficient sorting equipment. As the flexible supporters are lengthened when filling up the compartment and as the compartment is opened only at its one edge, timber pieces at the edge areas of the bag come into a rotating movement that breaks sharp edges of timber pieces thus lowering their quality. Further, there is the additional drawback that special triggering mechanisms are required for opening and closing the flexible supporters.